2,6-diaminopimelic acid, or 2,6-diaminoheptanedioic acid, is a normal constituent of bacterial cell walls that plays an important role in cell wall rigidity. Bacterial cell wall rigidity is thought to be maintained by virtue of peptide crosslinking bonds between diaminopimelic acid and D-alanine moieties. This function of diaminopimelic acid appears to be necessary in all gram negative bacteria and also for some members of the genus Bacillus. More particularly, the DL isomer of diaminopimelic acid appears to be involved in bacterial cell wall synthesis. That is to say, the asymmetric carbon atom adjacent to one of the carboxyl groups is in the D-configuration, whereas the asymmetric carbon atom adjacent to the remaining carboxyl group is in the L-configuration.
The metabolic synthesis of D,L-diaminopimelic acid occurs via the lysine biosynthetic pathway. The penultimate step in this pathway involves the epimerization of the L,L-isomer of diaminopimelic acid to the corresponding D,L-isomer utilizing the enzyme 2,6-L,L-diaminopimelate-2-epimerase (DAP-epimerase). Thus, in principle, any inhibitor of the enzyme DAP-epimerase should prevent the formation of D,L-diaminopimelic acid with a concomitant inhibition of bacterial cell growth.